1. Field of the Invention
The present invention relates to a closed-type drying system for drying agri-food products and more particularly, to such a closed-type drying system, which utilizes and complements the heat from sun radiation to dry agri-food products and, photocatalyst was sprayed within the chamber to kill the bacteria as catalyzed by ultraviolet of sunshine.
2. Description of the Related Art
Drying agricultural products is to lower the moisture content, to reduce the weight of volume, and to extend the preservation time or shelf life without affecting the taste. Taiwan utility model Patent No.203526 discloses a drying system for this purpose. This drying system comprises a drying chamber, an air blower adapted to blow air through the drying chamber, an evaporator adapted to condense moisture from hot wet air passing through the drying system, a condenser adapted to preheat air coming from the evaporator, and a heater adapted to heat air (to reach a specific temperature if needed) passing into the drying chamber. This design of drying system is functional; however it can save electric energy during operation. Taiwan utility model Patent Publication No.577534, (issued on Feb. 21, 2004) showed that the use of solar energy for drying agricultural products to reduce consumption of electric energy.